JPH01251198A - Storage-type fire alarm device - Google Patents

Abstract

PURPOSE:To prevent a false report and to improve the reliability of a device by deciding a fire when an abnormality state over a prescribed level elapses a prescribed storage time (slant detection) when a fire is monitored. CONSTITUTION:When a level outputted by a sensor is decided to be over a reference level A by comparing the level outputted by the fumes detection part FS and the reference level A, the value of a storage timer T stored in a memory area RAM 2 for time counter is increased one and the sensor output level SLV is stored in a RAM 1 for calculating the level slant. This operation is successively executed every fixed time, the oldest sensor output level is discarded when the sampling of N times is executed and newest data is stored. The slant SN of the stored data is calculated by using a least square method or an average vector method. The slant SN is compared with a reference slant K and the fire is decided when the SN is over the K. Then, a fire alarm TRX is outputted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a storage type fire alarm device that determines a fire abnormality based on the detected amount of heat, smoke, light, gas, or the like.

[Prior Art] Conventionally, storage type fire detectors and MTM type receivers are known as storage type fire alarm devices. These storage-type fire detectors and storage-type receivers detect fire phenomena such as heat, smoke, light, or gas that exceed a predetermined level, such as a fire discrimination level, and remain in that state for a predetermined period of time, i.e., a storage time. If it continues continuously, it is determined that there is a fire, and in the case of a storage type fire detector, a fire signal is sent to the receiver, and in the case of a storage type receiver, it is notified that a fire has occurred.

Furthermore, there are two types of storage type receivers, and the first type, as disclosed in Japanese Patent Publication No. 45-35862, has a detector that outputs a normal fire signal. When a fire signal is received from a sensor, the sensor is restored for a predetermined time, and if the sensor operates again within a second predetermined time after restoration, it is determined that there is a fire. In this case, an analog sensor is connected to the receiver, and when the digitized analog signal output from the sensor exceeds the fire detection level, a timer is activated. There is a known system that determines that there is a fire if the analog quantity signal continues to exceed the fire discrimination level during the fire.

In the conventional N\Ii type fire alarm system as described above, in any case, a fire is determined only when the physical quantity detection unit continuously exceeds a predetermined level for a predetermined period of time. For example, in the case of a photoelectric smoke sensor that detects smoke, this prevents non-fire alarms caused by transient smoke such as cigarette smoke.

However, in this case, the condition is that the detected amount continues to be at a predetermined level or higher, so for example, as shown in FIG. Thereafter, even if the fire phenomenon is decreasing due to extinguishing or other reasons, if the level is still above the predetermined level, the time t2 after a predetermined period of time has elapsed.
However, as shown in the lower part of FIG. 4, there is a problem in that a fire abnormality signal is issued. Further, even if smoke temporarily enters the environment and the sensor output level suddenly increases and then decreases in response, a fire abnormality signal will be issued in the same way, resulting in a non-fire alarm.

[Problems to be Solved by the Invention] In this way, conventional storage type fire alarm devices are activated only when a predetermined level is exceeded. For example, in the case of a photoelectric smoke sensor, a temporary There is a problem in that even though the detected amount decreases midway through the process like sexual smoke, if a predetermined level or higher continues for a predetermined period of time, a malfunction occurs.

[Means for Solving the Problems] The present invention has been made to solve the above-mentioned conventional problems. It is an object of the present invention to realize a storage type fire alarm device with high layer reliability by outputting a fire abnormality signal only when the tendency of the slope of the output level is equal to or higher than a predetermined slope.

Therefore, according to the present invention, there is provided a fire phenomenon detection section (FS) that detects the physical I related to a fire phenomenon and outputs a sensor output level (SLY), and fire discrimination based on the sensor output level from the fire phenomenon detection section. In the fire alarm device, the fire alarm device is equipped with a fire detection means for detecting a fire phenomenon, and a timer means (RAM2, step 305), and the time accumulated by the timer means is set to a predetermined accumulation time (step 305);
RAM1, step 3o8), which determines the tendency of the slope of the sensor output level from the time when the sensor output level reaches the predetermined value. level to the abnormal side, the time NWi is set by the timer means is longer than the predetermined accumulation time, and the slope determined by the slope determining means exceeds the predetermined slope (K) to the abnormal side. Provided is a storage type fire alarm device that determines that there is a fire when a fire occurs.

[Function] A fire is determined only when the sensor output level exceeds a predetermined level for a predetermined accumulation time or more, and the slope of the sensor output level exceeds a predetermined slope. Even if the sensor output level exceeds a predetermined level for a predetermined accumulation time, if the sensor output level is decreasing, it will not be judged as a fire, thereby further reducing the possibility of non-fire alarms. .

[Example 1] Hereinafter, an example of the present invention will be described using a photoelectric smoke sensor as an example. Prior to that, the operation of the present invention will be explained.

FIG. 1A and FIG. 1B are graphs showing two examples of smoke rising states for detailed explanation of the present invention,
In both figures, the upper row shows the sensor output level SLV (! axis) read at each sampling period as a function of time L (horizontal axis), and the lower row shows the sensor output level SLV (! axis) read at each sampling period as a function of time L (horizontal axis), and the lower row shows the sensor output level SLV (! axis) read at each sampling period as a function of time L (horizontal axis). The rate of change of the sensor output level SLY, ie, the slope SN (vertical axis), is also shown as a function of time t (horizontal axis).

Figure 1A shows a case where no fire action occurs, that is, no fire abnormality signal is issued, and the sensor output level S
When LV reaches a predetermined level A or higher at time t1, the accumulation time timer is activated and starts counting the accumulation time, and also starts storing N sensor output levels read at each sampling. Once sampling continues and N sensor output levels have been stored, in subsequent samplings the oldest sensor output level is discarded each time a new sensor output level is read, and in this way the memory is always stored. The new N sensor output levels are stored.

The accumulation time timer ticks, and the predetermined accumulation time T is reached.
When counting up 0, time L2 to t is calculated based on the latest N values from time t2 of the sensor output level read at each sampling.

The trend of the sensor output level between the two, ie, the slope SN, is determined. In this case, the slope sN is calculated by the least squares method, the mean vector method, etc. based on the values of the latest N sensor output levels. The slope SN at time t3 obtained in this way is shown in FIG. 1A to be smaller than the predetermined slope K, and as such is in a decreasing trend,
At this point, the sensor output level exceeds the predetermined level A, but no fire abnormality signal is output.
The slope SN is calculated in the same way based on the latest N sensor output levels for each sampling, and if the slope SN exceeds a predetermined slope, a fire abnormality signal is output at that point. In Figure 1A, the slope S of the sensor output level is
N does not exceed , and the sensor output level continues to decrease until it falls below the predetermined level A at time t, so at this point the accumulation time timer is cleared and the system returns to the normal monitoring state. return.

FIG. 1B shows a case where a fire action is performed, that is, a fire abnormality signal is issued, and when the sensor output level reaches a predetermined level A or higher at time L5, the accumulation time timer is activated as well. At the same time as counting of accumulation time is started, N sensor output levels read every sampling are started to be stored.

The accumulation time timer sets the predetermined accumulation time T at time t.
After counting up 0, the trend of the sensor output level from time 1 to time t7, that is, the slope sN, is determined based on the latest N values from time t6 of the sensor output level read at each sampling, and the slope sN is calculated as follows. Since the slope sN at time t, which is calculated as shown in FIG. 1B, is shown to be at least a predetermined slope, a fire abnormality signal is output at this point.

After the accumulation time has expired in this way, the fire abnormality signal is output only when the trend, that is, the slope, of the sensor output level calculated based on the latest N sensor output levels is in an upward trend. Malfunctions due to temporary environmental changes such as cigarettes and the like are prevented, and a highly reliable N-product alarm device can be realized.

Note that the predetermined slope K is appropriately set according to environmental conditions, etc., and Figures 1A and 1B show the case where it is set to a negative value close to O for safety reasons. .

In addition, in FIGS. 1A and 1B, the time interval t2 to t or t6 to t for storing N sensor output levels is
Although shown as being shorter than the predetermined accumulation time T0, the number of senna output levels to be stored may be changed as appropriate depending on the environmental conditions, for example, by setting the number of senna output levels over the same time interval as the predetermined accumulation time T0. It is possible.

Furthermore, the predetermined level A, the predetermined accumulation time T0, and the predetermined inclination K are determined based on the purpose and height of the room in which the sensor DE is installed.
It can be set as appropriate depending on the volume, time, presence or absence of noise, etc.

FIG. 2 shows an embodiment in which the present invention is applied to a smoke-type fire detector. In FIG. 2, RE is a receiver, L is a plurality of wires, for example, a pair of power and signal lines, and The circuit portion DE shown within the chain line is a plurality of fire detectors connected to the receiver RE by power and signal lines, and only one fire detector is shown here.

In the fire detector DE, FS is a fire phenomenon detection section, and in this embodiment, a scattered light type smoke detection section is shown.

MPLJ is a microcomputer, O20 is an oscillation unit that oscillates a clock, ROMI is a storage area for the program shown in the flowchart in Figure 3, ROM2 is a storage area for a predetermined level A, and ROM3 is one of the fire discrimination criteria. ROM4 is a storage area for a predetermined slope K of the senna output level as a fire discrimination standard; RAM1 is a storage area for N sensor output levels SLV read from the fire phenomenon detection unit FS. RAM2 is a storage area for a time counter as a timer for counting the accumulation time T, 1' (AM3 is a work area, and TRX is a transmitting/receiving unit connected to the receiver RE. .

In addition, the smoke sensor, that is, the smoke detection chamber of the smoke detection unit FS includes a light emitting diode LED that is pulse-lit at a predetermined period by an oscillation circuit 12 and a light emitting circuit 14, and a light emitting diode LED that is pulse-lit at a predetermined period by an oscillation circuit 12 and a light emitting circuit 14. Solar cell S receiving scattered light
The output from the solar cell SB is amplified by an amplifier 18 via a light receiving circuit 16, and then converted to a digital signal by an analog/digital (A/D) conversion circuit 20, and then sent to an interface. It is sent to the microcomputer MPtJ side via the I/F.

In the case of the embodiment shown in FIG. 2, a fire detector DE is connected to the receiver RE, and the fire detector DE sends only the resulting fire abnormality signal to the receiving fiRE, and the fire detector DE sends only the resulting fire abnormality signal to the receiving fiRE. Since the DE is not polled, the transmitting/receiving unit TRX functions only as a fire signal transmitting unit.

The operation shown in FIG. 2 will be explained using the flowchart shown in FIG.

After the initial setting (step 301), the smoke detection unit
The sensor output level SLV is read from S to the work area RAM 3 via the interface I/F (step 30
2) Compare it with a predetermined level A stored in the storage area ROM2 (step 303). As a result of the comparison, if the sensor output level SLY is smaller than the predetermined level A (N in step 303), the sensor output level Storage area R
The sensor output level stored in AM1 is cleared and T=0 (step 304), and the next sensor output level SLV is read in step 302 at the next sampling time.

As a result of the comparison, if it is determined that the sensor output level SLY is equal to or higher than the predetermined level A (Y in step 303),
), if the sensor output level SLY is equal to or higher than A at first, then P
The storage area R for the time counter from the time it was set to the current time
The value of the accumulation timer T accumulated in AM2 is incremented by one (step 305), and after the increment, the sensor output level SL is
V is stored in the memory area RAM1 for calculating the slope of the sensor output level (step 306), and the incremented accumulation timer T is then compared with a predetermined accumulation time T0 stored in the memory area ROM3. be done. (Step 307).

As a result of the comparison, if it is determined that the value of the accumulation timer T is smaller than the value of the predetermined accumulation time T0 (N of step 307
), a new sensor output level is read every sampling period in step 302, and the operations from step 303 are performed in the same manner.

In this way, the sensor output level SLY is determined and the level A
If sampling is performed N times after the above, the storage area RAMI will become full, and the sensor output level SL will be read from the next (N+1)th sampling.
When storing V in the storage area RAM1, step 30
At 6, the oldest sensor output level of N is discarded.

Therefore, after N samplings after the sensor output level reaches or exceeds the predetermined level A, the latest N sensor output levels are always stored in the storage area RAM1.

As a result of the comparison in step 307, if the value of the accumulation timer T is greater than or equal to the predetermined accumulation time T0 (step 30
7 Y), calculate the trend or slope of the sensor output level over N periods based on the latest N sensor output levels stored up to the present time in the storage area RAM1,
This is stored in the work area RAM 3 as an SN (step 308).

Here, various methods such as the least squares method, the mean vector method, etc. can be used as a method for calculating the slope based on the N sensor output levels.

When the slope sN of the current sensor output level is stored in the working area RAM3, the slope SN is stored in the storage area ROM.
If the slope is greater than or equal to SN (step 309
Y), as explained in Fig. 1A and 1BI21, since the two conditions of T≧T0 and SN≧ are satisfied, it is determined that a fire abnormality has occurred, and a fire signal is output from the fire signal sending unit TRX. An action is taken (step 31
0).

If the trend of the sensor output level, that is, the slope SN is
If smaller (N in step 309), step 30
Returning to step 2, the next sensor output level is read at the next sampling period. In other words, the calculations in steps 305 and 308 are performed based on the sensor output level read at each sampling period, and the sensor output level SLY
While the value of the M product timer T is determined to be equal to or higher than the predetermined level A in step 303, the value of the M product timer T reaches the predetermined accumulation time T0.
(Y in step 307), and the slope s
If the number of fires exceeds N (Y in step 309), a fire action will be taken, and steps 307 and 0 will be executed.
9, before it is determined that T≧T0 becomes sN≧,
If the sensor output level SLV falls below the predetermined level A (N in step 303), the contents of T and RAMI are cleared (step 304) and the normal monitoring state returns.

In the above embodiment, the present invention is applied to a fire alarm device in which the fire detector DE performs fire discrimination and sends a fire signal and/or an address signal to a receiver. The so-called analog type fire detector is an analog type fire detector that sends out a physical quantity signal of the detected fire phenomenon, and a receiver or repeater performs fire discrimination based on the physical quantity signal sent from the analog type fire detector. It is also possible to apply the present invention to fire alarm devices.

In this way, when the present invention is applied to an analog fire alarm device in which a receiver or a repeater receives an analog quantity signal converted into a digital signal from an analog detector to detect a fire, , In FIG. 2, the receiver RE is provided with a microcomputer MPU, and
From the sensor DE, ROM1 to R, 0M4 and RAM1. R
Move AM2 etc. to the receiving fiRE. In addition, the receiver RE
The number of RAMIs and RAM2s to be relocated is equal to the number of analog sensors to be connected. and receive fiRE
A program was added to the ROMI that was relocated to the ROMI to poll multiple analog sensors and sequentially read analog quantity signals, and each time an analog quantity signal was read, fire discrimination was performed according to the flowchart in Figure 3.

On the other hand, the sensor DE determines whether or not it has received polling from the receiver RE, reads the sensor output level SLV from the fire phenomenon detection section FS when polling is received, and transmits the sensor output level SLV from the transmitter/receiver section TRX to the receiver r (H A ROM is provided that stores a program to be sent to the computer.

[Effects of the Invention] As described above, according to the present invention, the predetermined accumulation time elapses while the sensor output level remains above the predetermined level, and the trend, that is, the slope, of the sensor output level over a certain period up to the present is determined. Since the fire abnormality signal is output only when the two conditions of being equal to or higher than a predetermined value are satisfied, it is possible to realize a more reliable storage type fire alarm system that does not cause false alarms. .

[Brief explanation of the drawing]

1A and 1B are graphs for explaining the present invention in detail, FIG. 2 is a block circuit diagram showing a fire alarm system according to an embodiment of the present invention, and FIG. 3 is a graph for explaining the present invention in detail. FIG. 4 is a flowchart for explaining the operation, and FIG. 4 is a graph for explaining the prior art. In FIG. is the program storage area, R
OM2 is a predetermined level storage area, ROM3 is a predetermined accumulation time storage area, ROM4 is a predetermined slope storage area, and RAM1
is a sensor output level storage area, RAM2 is a time counter storage area, RAM3 is a work area, A is a predetermined level, T
o is a predetermined accumulation time, and K is a predetermined slope. Patent applicant Nomi Disaster Prevention Industry Co., Ltd. Figure 2 Figure 3

Claims (1)

[Scope of Claims] A fire phenomenon detection section that detects a physical quantity related to a fire phenomenon and outputs a sensor output level, and a fire discrimination means that discriminates a fire based on the sensor output level from the fire phenomenon detection section. A fire alarm device comprising: timer means for accumulating the time period during which the value of the sensor output level from the fire phenomenon detection section exceeds a predetermined level on the abnormal side; slope determination means for determining a slope trend of the sensor output level from the point in time when the sensor output level exceeds the predetermined level to the abnormal side; and when the time accumulated by the timer means is longer than the predetermined accumulation time and the slope determined by the slope determination means exceeds the predetermined slope to an abnormal side, it is determined that there is a fire. A storage type fire alarm device characterized by: